Counterbalancing device for vulcanizing molds



Nov. 6, 1928. 1,690,625

P. DE MATTlA COUNTERBALANCING DEVICE FOR VULCANIZING MOLDS Filed Sept-27, 1926 2 Sheets-Sheet 1 INVENTOR TTORNE VS Nov. 6, 1928. 1,690,625

P. DE MATTIA Y COUNTERBALANCING DEVICE FOR 'VULCANIZING MOLDS Filed p27, 1926 2 Sheets-Sheet 2 555a, mew

%g4 ZATTOR/YZYJ Patented Nov. 6, 1928.

UNITED :STATES- PATENT OFFICE.

PETER DE maria, or PASSAIC, NEW JERSEY, ASSIGNOR, BY unsrm ASSIGNMENTS,TO NATIONAL RUBBER MACHINERY COMPANY, or AKRON, omo, A oonrom'rxon OFOHIO.

COUNTERBALANCING DEVICE FOR VULCANIZING MOLIDS.

Application filed September 27, 1926. Serial No. 137,845.

This invention relates to improvements in molds such as are used in thevulcanization of automobile tires, inner tubes, and the like, .and hasparticular reference to molds of the type having hinged sections, one ofwhich may be swung relative to the other to open the mold.

For reasons well understood in the art, it is desirable that the moldmay be quickly opened and closed for insertion and removal of the work.The movable section or cover member of such a mold is quite heavy, and

tiil) in order to ease the work of the operator and to speed up theoperation, Various types of counterbalance weights, overhead hoists, andthe like have been used. Such prior art devices have not beensatisfactory, however, for several reasons. Usually the molds aredesigned with a view to economy in occupied floor space, and thereforecounterbalance weights must be suspended on a short leverage to positionthem close to the base of the mold. Because of this limitation inleverage, the weight must be much heavier than the movable mold section,in some instances a thousand pounds, which is excessively bulky. Suchbulky and heavy counterbalance weights are particularly undesirable inhorizontal rocking molds, which require periodic tilting, such as fordraining condensation from the heating chambers because they render thetilting difficult and necessitate more complicated steam and drain pipeconnection. Hoists have been used in some instances, suspended above themolds, but they have been expensive to install and maintain, and not soconducive to rapid operation.

These and other objectionable features of the prior art are overcome bythe present invention which contemplates the use of formed of hingedsections, with a spring member having one of its ends anchored to theswinging section and its other end actmg against a stationary portion ofthe machine in such a manner as to substantially counterbalance saidswinging section.

Another feature is the provision of such a counterbalancing spring withmeans for varying the tension as desired.

Another feature is the provision of such a counterbalancing device forsectional molds wherein the spring is normally under compression andenclosed within a protective casing on top of the movable section.

Another feature is the provision of such a counterbalanced mold sectionwith a novel and simplified lock for holding it in its open position.

Other features and advantages will be apparent from the followingdescriptionwhen taken in connection with the accompanying drawings,wherein a preferred em- Figure 1 is a side elevation of a mold equippedwith a counterbalance mechanism in accordance with this invention, thelockmg ring being shown in unlocked position;

Figure 2 is a top plan view thereof, with the locking ring in lockedposition;

Figure 3 is a fragmentary detail view of the mold hinge and itsconnecting means for one end of the counterbalance spring;

Figure 4 is a fragmentary elevation of the mold looking toward the lockoperating. means in the direction of arrow A in Figure 2; and

Figure 5 is a detail sectional view on the line 5-5 of Figure 2. i

The invention has been shown in the drawings as applied to a tubevulcanizing mold of the horizontal rocking type, but it is equallyapplicable to molds of the stationary type, as well as to molds forvulcanizing tire casings and articles other than inner tubes. Such atube curing mold may comprise a pair ,of opposed mold sections 1 and 1having hinge members 2 and 2* respectively, connected together as at 3by a to form an annular vulcanizing chamber 4 into which "the article tobe treated is placed, said vulcanizing chamber being surrounded byheating chambers or steam jackets 5 and 6. In the broader aspects of theinvention, any ordinary means maybe employed for locking the two moldsections together to resist internal pressure 1 may be provided with aplurality of down,

wardly extending hook members or lugs 7 adapted to engage a slotted ring8 which is rotatably support-ed in any suitable manner against a guideflange 9 on the lower or fixed section 1*. The hook members 7 aresuitably spaced around the circumference -of the mold section 1, asshown, and their lower ends 10 extend inwardly 1n such manner as tostraddle portions of the flange 9 and ring 8, and to bear against thelower surface of said ring (see particularly Fig.

I 5). The flange 9 is formed with slots or recesses 11 in radialalignment with the hook members 7, and the ring 8 is similarly providedwith recesses 12 which, when aligned with the recesses 11, as shown in Fig. 1, permit passage of the ends 10 of the hook members during swingingmovement of the mold section 1. At one side of the recesses 11, thelower surface of the ring 8 is beveled or inclined, as at 13, to formwedging surfaces for engagement with the ends 10 of the hook members(which may or may not be"oppositely beveled, as desired) to positivelydraw the two sections together when the ring is partially rotated to aposition as shown in Fig. 2. Such rotation is effected through a gearsegment or rack 15, secured to the ring 8, and meshing with a pinion 16on the lower end of a shaft 17, which latter is provided at its upperend with a hand wheel 18' (Fig. 4).' In the illustrated embodiment ofthe invention, the shaft 17 is shown as journalled at 19 to the movablemold section 1, but it may be mounted on the section 1 if desired.

The lower mold section 1 is supported by a pedestal 22, which, in thecase of a rocking mold, is fitted with trunnions 23 having pivotalconnection at 24 with said lower mold section. To assist in the supportof the section 1*, pairs of links 25 and 26. are mounted at oppositesides of the pedestal, said links being pivoted together as at 27, withthe upper ends of links 25 attached at 28 to the mold section 1*, andthe lower ends of links 26 attached at 29 to the pedestal 22. Alsopivoted to the mold section 1- at its underside is a locking rod 30having an upwardly extending loop portion 31 forming a recess forengagement with a pin 32 which extends outwardly from the pedestal 22.-WVhen the pin 32 is within the loop 31, as shown in Figure 1, the moldis firmly held in its horizontal position, and may be unlocked by meansof a push-rod 33 which actuates a bell-crank lever having one of itsarms 34 engaging the locking rod 30.

The mechanism thus far described is illustrative of one type of mold towhich the counterbalance mechanism, which is an important feature ofthis invention, may be applied. Said counterbalance 'mechanism ispreferably mounted above and rearwardly of the mold, and includes aspring housing or guide sleeve 35 which is supported between a standardor post 36 secured to the swinging mold section 1 adjacent the frontedge thereof, and a bracket member 37 attached to the lower mold section1 at the side of the hinge connection 3 opposite the post 36.

The bracket member 37 may be in the form of a flat plate having anenlarged upper end 38 which is preferably bifurcated and provided withrearwardly disposed and inclined notches 39 for reception of oppositelydisposed pins or bolts 40. As best shown in Figure 3, the bracket 37carries a segmental gear 41, the teeth of which are selectivelyengageable by a detent 42 carried by the hinge member 2''. Thus thebracket 37 may be adjusted about the axis of the hinge pintle at 3 forthe purpose of settingit approximately for the tension desired in thecounterbalance.

The pins or bolts are transversely disposed in a cylindrical sleeve 43which is mounted in the bifurcated upper end 38 of the bracket'37, andextending longitudinally through said sleeve 43 is one end of atension-rod 44, having a threaded extremity to receive an adjusting nut45.

The opposite end of the tension rod 44 extends into the spring housing35 through a closure cap 47 and is fitted with a collar or head portion46. Compressed between the cap 47 and the collar 46 is a coiled spring48, the force of which may be finely adjusted by turning the nut 45. Theother end 01 the spring housing 35 is closed by a cap 49 having a yokeportion 50 for connection 10 the post 36 by a clevis pin or bolt 51. Theproportions and disposition of the parts are such that the spring andits cooperating parts are inclined with respectto the upper surface ofthe mold, whereby said spring exerts its lifting force in a line obliqueto the axis of the mold.

From, this it will be apparent that the spring 48, being undercompression, effectively counterbalances the weight of the swinging moldsection, and in View of the fact that the spring housing 35 is pivotedto the post 36, and with its other end slidluJ,

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able relative to the tension rod 44:, the counagainst the fixed section1".

positions of said swin ing mold section.

For the purpose 0 reinforcing the post 36, an angularly disposed brace52 has its upper end secured to the post, while its lower ,end isanchored in a boss 53 in the mold section 1. Also secured to the moldsection 1, preferably at the front thereof is a handle 54 by means ofwhich said section may be swung away from the lower section 1 to openthe mold, and to facilitate tilting of the closed mold on its pedestal.

In order to lock the movable mold section 1 in its open position, a rod55 is pivoted by means of an eye 55 to one of the pins 40, and attendsforwardly beside the Spring housing 35. Adjacent to its forward end therod 55 is formed with a double offset to The offset forming the latchmember 56 is at an acute angle to the rod-55, and the parts are soproportioned that the handle portion 57 rests upon the projecting end ofthe pin 51 when the mold is closed. Because of the fact that the rod 55and the cover member 1 are pivoted eccentrically with respect to eachother, the distance between the pins 40 and 51 becomes shorter as thecover memher is moved upwardly, as shown in Fig. 1, until it reaches themaximum required opening, when the latch member 56 drops down andengages the projecting end of the pin 51. The inclination of the latchmember provides a positive grip whereby the mold section may bemaintained in its raised position. I

Live steam or other suitable heating medium may be supplied to theheating chambers 5 and 6 from an inlet pipe 58 and through conduits 59,60, 61, and 62. some of said conduits having swivel connections 63, asshown in the drawings. Similarly a drain pipe 64 communicates with thechambers 5 and 6 through conduits 65, 66, and 67, having swivelconnections 68. The pipes 58 and 64: are firmly supported by a cross-bar69 which is carried at the extremity of a horizontal arm 70 attached tothe pedestal 22.

In using the device, the tube or other article to be vulcanized isplaced within the mold chamber at in the usual manner and the movablemold section 1 is swung down In such move ment the ends 10 of thelocking lugs 7 pass through their respective recesses 11 and 12, andafter said movable mold section has come to rest against the relativelyfixed section, the locking ring 8 is partially rotated by means of thehand wheel 18. Thus the inclined bearing surfaces 13 are caused toengage with the ends 10 of. the locking lugs to positively draw the twomold sections together and to lock them in such relationship. Thearticle may then be subjected to the vulcanizing process, as usual, atthe completion of which the mold may be quickly opened by operation ofthe hand wheel 18 to unlock the hook members 7. The operator then graspsthe handle 54 and swings the top mold section 1 upwardly about its hingeconnection-3. The weight of the cover member is substantiallycounterbalanced by the spring 18 and its associated parts as has beenalready described, thus reducing the effort required of the operator,and thereby quickening said operation. When the swinging mold section 1reaches a position slightly beyond that indicated by dotted lines inFig. 1, the latch member 56 engages the end of pin 51 and holds saidmold section in raised position, leaving the operator the use of bothlands for removing the cured article and inserting another uncuredarticle in the mold. In reclosing the mold, the operator again graspsthe handle 57, relowers the mold section, and looks it in place for thenext operation. If it is desired to vary the lifting force of themechanism; this may be easily accomplished by means of the adjusting nut4:5 or the segmental gear 41.

lVhen it is desired to tilt or rock the mold, such as for drainingcondensation from the heating chambers 15 and 16, the loops 31 of thelocking rod 30 may be disengaged from the pin 32 through theinstrumental'ity of bell-crank lever 34 and push-rod 33. The entire moldmay then be moved about the axis of the trunnions 23. Since the weightof the counterbalancing mechanism is applied to the mold on oppositesides of the trunnions 23, the tilting or rocking referred to can beconveniently carried out with little or no extra effort. Furthermoresince there is no bulky weight depending from the mold, as in certainprior art molds, the steam and drain pipe connections may be made moreeasily.

From the foregoing it will be obvious that a substantial advance hasbeen made in the art by the provision of my simplified locking means andeffective counterbalance mechanism. The invention is, of course,susceptible of numerous modifications and the right is herein reservedto makesuch changes as fall within the scope of the appended claimswithout departing from the spirit of the invention.

Having thus described my invention, what I claim is:

1. In a vulcanizing mold, a normally horizontal fixed mold section, amovable mold section hinged with reference thereto, counterbalancingmeans overlying the movable mold section and movable therewith, andmeans for tilting the mold sections as a unit.

2. In a vulcanizing mold, a normally horizontal fixed mold section, amovable mold ill) IUU

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section hinged with reference thereto, counterbalancing means in theform of a coiled spring carried by the movable section and actinv toexert a lifting force thereon, a pedestaI for supporting the fixed moldsection, and means to permit tilting of said fixed mold section withreference to the pedestal.

3. A rockable vulcanizing mold, comprising a normally horizontal fixedmold section, a movable mold section hinged with reference thereto,counterbalancing means in the form of a compression spring carried bythe movable section and overlying the same, said spring acting to exerta lifting force on the movable mold section, and means for tilting themold sections as a unit.

4:. A r'ockable vulcanizing mold, comprising a normally horizontal fixedmold section, a movable mold section hinged with reference thereto, abracket secured to said fixed mold section, a post carried by themovable. mold section, said bracket and post being relatively disposedat opposite sides of the axis of the hinge pintle, and yieldingcounter-balancing means connecting the bracket and said post andexerting a lifting force on said movable mold section.

5. In a vulcanizing mold, a relatively fixed mold section, a movablemold section hinged with reference thereto, a bracket motinted on thefixed mold section, a compression spring extending longitudinally overthe movable section, means for connecting one end of the spring in fixedrelation to said bracket, and'means for connecting the other end of thespring to the movable mold section in such a manner as to exert alifting force thereon.

6 In a vulcanizing mold, a relatively fixed mold secton, a movable moldsection hinged with reference thereto, a bracket mounted on the fixedmold section, a compression spring, a tension rod pivoted to the bracketand extending through the spring, said tension rod having a collar atits outer end to form an abutment for one end of the spring, and meansfor yieldingly connecting the opposite end of the spring to the movablemold sect'on to exert a lifting force thereon.

7. In a vulcanizing mold, a relatively fixed mold section, a movablemold section hinged with reference thereto, a bracket mounted on thefixed mold section adjacent the hinged side of the mold, a tension rodpivoted to said bracket and extending overthe movable mold section, saidtension rod being prov'ded at its outer end with a collar to form anabutment, a spring encircling a portion of the tension rod and havingone end ongaging against said abutment, and means for connecting theother end of the spring to the movable section, and to compress thespring to exert a lifting force on said movable section.

8. In a vulcaniz'ng mold, a relatively fixed mold section, a movablesection hin ed with reference thereto, a bracket mounte on said fixedmold section adjacent its hinged edge, a post carried by the movablemold section, a guide sleeve having one of its ends pivoted to saidpost, and its free end disposed toward said bracket, a tension rodpivoted to the bracket ec'centrically with respect to the axis of themold hinge, the other end of said tension rod being in the form of acollar and having sliding engagement within the guide sleeve, and acompression spring .disposed between said collar and the free end of theguide sleeve whereby to exert a lifting force to assist opening movementof the movable mold section.

9. In a vulcanizing mo'ld having a pair of opposed mold sections hin edwith reference to each other, means torholding the mold sections inseparated position, said means comprising a rod pivoted to one of themold sections eccentrically with respect to their hinged connection, alatch member carried by the rod, and means on the other mold sect'on forengaging with the latch member when the mold sections are separated.

10. A vulcanizing mold having a pair of opposed mold sections h'ngedwith reference to each other, said mold sections having steam jacketsand being normally horizontal when closed and in use, means foradjustably supporting the mold sections whereby to permit them to betilted to drain, and a counter-balancing spring to assist in opening themold, said counterbalanc'ng spring being carried by the tiltable moldsections and having its weight distributed on opposite sides of the axison which the mold sections are tilted.

In testimony whereof, I have afiixed my signature hereto.

PETER DE MATTIA.

